architecture-patterns

Architecture patterns enforce decoupled layers by ensuring controllers call repository methods instead of directly accessing the database. This maintains strict separation of concerns and preserves domain entity purity in FastAPI backend development.

The repository pattern decouples database access by acting as an intermediary layer between controllers and the database. It ensures thin controllers interact only with repository methods, preserving pure entities and maintaining architectural integrity during backend refactoring.

Refactor a FastAPI controller by replacing direct database calls with repository method invocations. This creates thin controllers that handle request routing while keeping pure entities separated from data access logic.

Yes, this architecture enforcement applies to backend code reviews and refactoring. It evaluates code against the 7 Core Pillars to prevent architectural drift and ensure adherence to specific directory structures and interaction patterns.

A FastAPI controller directly accessing the database violates clean code architecture by bypassing the repository pattern. This breaks decoupled layers, causes architectural drift, and destroys the strict separation of concerns required for pure entities.

You need explicit agent I/O contracts in backend architecture when defining interaction patterns between controllers, repositories, entities, and domain services. This enforces strict dependency boundaries and maintains architectural integrity across decoupled layers.